Lactase Benefits, Uses, Dosage, Side Effects and Interactions - Dr. Axe

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What Is Lactase? How It Helps Manage Lactose Intolerance & More


Lactase - Dr. Axe

If you’ve been diagnosed with lactose intolerance or you suspect you’re dealing with this condition due to symptoms like bloating and gas after consuming dairy products, you may consider taking lactase pills.

How does lactase work, and are lactase pills safe? Below we’ll cover the function of lactase enzymes and potential benefits of taking it in supplement form, plus tips on managing lactose intolerance if you prefer not to only rely on supplements.

What Is Lactase?

Lactase is an enzyme produced by humans (and many other mammals and organisms) in the small intestine.

Lactase enzymes (also sometimes called lactase-phlorizin hydrolase) are essential for proper digestion of dairy products, including milk. That’s because this enzyme breaks down lactose, a sugar naturally found in milk that contributes to its sweetness.

The specific location in the small intestine where lactase is produced is called the “brush border,” which is made up of cells that line the walls of the small intestine (intestinal epithelial cells). These cells have small, finger-like microvilli that absorb nutrients from food so they can be passed into the bloodstream and dispersed as needed.


What foods contain lactase? Lactase itself is not found in foods, but lactose is (a type of sugar).

Some examples of high-lactose foods include:

  • cow’s milk (all types)
  • goat’s milk
  • ice cream
  • soft-serve frozen yogurt
  • ricotta cheese and other soft cheeses
  • sour cream
  • butter
  • whey protein powders
  • buttermilk
  • puddings/custards

Because these foods are high in lactose, people who don’t produce enough lactase have trouble digesting them. In fact, some findings suggest that around 70 percent of the world’s adult population may be lactase deficient, especially those of East Asian, West African, Arab, Jewish, Greek or Italian descent.

Health Benefits

What does the lactase enzyme do to contribute to overall health? Here are some of its roles and benefits within the human body:

1. Helps with Proper Digestion of Milk/Dairy

The most important job that the lactase enzyme has is catalyzing the breakdown of lactose (a disaccharide milk sugar), turning it into the simple sugars called glucose and galactose.

When mutations occur in the genes that control the production of lactase, resulting in less output, lactase deficiency (a form of lactose intolerance) develops. This results in the inability to digest lactose.

Lactose that is not absorbed in the gastrointestinal tract undergoes fermentation in the colon by bacteria. This leads to symptoms like increased production of gas, stomach bloating, diarrhea, pain and general “intestinal distress.”

There are three types of lactose intolerance that can prevent proper digestion: primary, secondary, and congenital or developmental. Different factors cause the different types, and they can also range in terms of severity of symptoms.

2. Helps Milk Be Turned Into Energy

Production of lactase is typically highest in humans during infancy, since milk (breast milk or formula) is normally the only food that infants consume. High production of lactase helps infants and babies absorb the sugars and other nutrients available in milk.

However, as humans age, the ability to produce enough lactase often declines.

As mentioned above, lactase enzyme turns lactose into glucose and galactose, simpler sugars that are also able to be used by adults for energy. These sugars are also coupled with protein, healthy fats, and many vitamins and minerals within milk (full-fat whole milk), making it a nutrient-dense food for those who can tolerate it.

3. Can Help with Management of Lactose Intolerance

Unfortunately , there’s evidence that many adults have difficulty digesting lactose properly, due to low levels of lactase.

There is currently no permanent cure for lactose intolerance, which is considered a lifelong/chronic condition that can only be managed. Permanent treatment isn’t possible (at least not yet) because no medication works to increase the amount of lactase your small intestine makes.

However, there are steps you can take to manage symptoms and avoid complications, including supplementing with lactase (more on this below) to support digestion.


Where is lactase found? While the human body makes it in the small intestine, you’ll also find this enzyme in supplement form, within lactase pills and drops.


These supplements are most often made from beta-galactosidase, a compound derived from the fermentation of the fungi Aspergillus niger or Aspergillus oryzae. 

People with lactose intolerance can take lactase enzyme supplements before eating foods that contain lactose/dairy to help their bodies digest the lactose sugar and limit symptoms. These supplements are forms of digestive enzymes that aid in the breakdown of nutrients, assisting in efficient digestive function

Taking specially formulated digestive supplements often provides a safe treatment for digestive malabsorption disorders, including lactose intolerance.

One of the most popular lactase enzyme supplements on the market is Lactaid, which is available over-the-counter (without a prescription). You can take lactase in pill/table form or as drops that are added directly to milk.

Several drops (about three of four) can also be added to breast milk or formula to support digestion in infants.

How should you use lactase enzyme supplements?

It’s recommended that you take tablets just before a meal or snack. (Consuming dairy in small amounts as part of a balanced meal can further help digestion.)

Drops can be added to a carton of milk or to individual servings.

Lactase enzyme pills usually come in doses between 3,000 and 9,000 international units per tablet. (This is the amount found in Lactaid Original and Lactaid Fast Act.)

Read directions carefully, and choose the dose that’s recommended based on your age and symptoms.

Risks and Side Effects

Are lactase pills safe? They are generally considered safe when used in appropriate amounts.

However, if you depend on them too much and overuse them, they may cause some side effects — plus they aren’t a “cure” for lactose intolerance.

Does lactase have side effects? If you have a pretty severe case of lactose intolerance, taking lactase pills might not do enough to prevent symptoms like abdominal pain, cramping, bloating, gas and diarrhea.

In this case, lactase products that help digest lactose will not solve the underlying problem and may not be a good long-term solution.

Rather than relying on taking lactase pills on an ongoing basis (potentially for your whole life) in order to manage digestive symptoms, you might want to take other steps instead that support your digestive system. Here are some ways to deal with lactose intolerance that don’t involve taking lactase pills or drops:

  • Reduce the amount of dairy foods in your diet, or choose only lactose-reduced or lactose-free milks.
  • It’s important to include calcium-rich foods in your diet if you avoid dairy products, as well as to get enough vitamin D (from the sun and/or supplements). Eat plenty of foods high in calcium, such as broccoli, leafy greens, beans, salmon, sardines and almonds. Studies indicate that these steps can help protect your bones and support cardiovascular health.
  • You can experiment with eating yogurt and aged cheeses to see if these are better tolerated than milk. Yogurt is fermented and contains active cultures (beneficial probiotics) that can help with digestion, often even among people with lactose problems. Aged, hard cheeses contain less lactose and are usually tolerated in small amounts.
  • Read food labels carefully so you know which foods contain milk/dairy, including boxed, canned, frozen and prepared foods.
  • Take a daily probiotic supplement, which supports digestive health, a healthy balance of gut microbiota and nutrient absorption. You can also obtain live or active cultures from fermented foods like yogurt, kefir, kombucha and fermented vegetables.

Another thing to point out is that it’s important to distinguish between lactose intolerance and a dairy allergy, since lactase pills won’t help someone with an allergy.

An allergy to milk is an autoimmune reaction against certain milk proteins. Reactions are often due to a negative response to consuming either the casein protein or whey protein found in milk/dairy, rather than from a lack of lactase enzymes.

Drug Interactions

Lactase pills and drops do not have any known severe interactions with other drugs. However, if you do take medications and are experiencing signs of lactose intolerance, it’s best to talk to your doctor about supplementing before beginning to do so on your own.

If you’re diabetic, make sure you understand how consuming dairy may affect your blood sugar.

You’ll also want to get your pediatrician’s advice about giving lactase to your infant or young child. Pregnant/breastfeeding women are typically advised to avoid supplementing with it unless their doctors decide that it’s safe.


  • Lactase enzyme’s function is to help break down lactase, a sugar naturally present in milk. Lactose is a disaccharide sugar containing glucose and galactose units, which need to be broken down in order to be used for energy.
  • When you can’t break down the lactose into its component sugars, it results in lactose intolerance. For people who have lactose intolerance, lactase pills and drops (sometimes with digestive enzymes and probiotics) can be used to manage symptoms that occur when eating dairy foods.
  • If you don’t want to rely on supplements to control your symptoms, try cutting dairy products from your diet (including milk, ice cream, yogurt and cottage cheese) and getting calcium instead from things like greens, broccoli, nuts, beans and fish.

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